Fluid Flow
LAMINAR AND TURBULENT FLOW
LAMINAR AND TURBULENT FLOW
The characteristics of laminar and turbulent flow are very different.
To understand why turbulent or laminar flow is desirable in the
operation of a particular system, it is necessary to understand the
characteristics of laminar and turbulent flow.
EO 1.9
DESCRIBE the characteristics and flow velocity profiles
of laminar flow and turbulent flow.
EO 1.10
DEFINE the property of viscosity.
EO 1.11
DESCRIBE how the viscosity of a fluid varies with
temperature.
EO 1.12
DESCRIBE the characteristics of an ideal fluid.
EO 1.13
DESCRIBE the relationship between the Reynolds
number and the degree of turbulence of the flow.
Flow Regimes
All fluid flow is classified into one of two broad categories or regimes. These two flow regimes
are laminar flow and turbulent flow. The flow regime, whether laminar or turbulent, is important
in the design and operation of any fluid system. The amount of fluid friction, which determines
the amount of energy required to maintain the desired flow, depends upon the mode of flow.
This is also an important consideration in certain applications that involve heat transfer to the
fluid.
Laminar Flow
Laminar flow is also referred to as streamline or viscous flow. These terms are descriptive of
the flow because, in laminar flow, (1) layers of water flowing over one another at different
speeds with virtually no mixing between layers, (2) fluid particles move in definite and
observable paths or streamlines, and (3) the flow is characteristic of viscous (thick) fluid or is
one in which viscosity of the fluid plays a significant part.
Turbulent Flow
Turbulent flow is characterized by the irregular movement of particles of the fluid. There is no
definite frequency as there is in wave motion. The particles travel in irregular paths with no
observable pattern and no definite layers.
Rev. 0
Page 17
HT03

